Grinding machine



W. E. TRENT.

GRINDlNG MACHINE. APPL1cA|-|oN man sLP|.3, 1920.

1,406,109. Patented Feb. 7, 1922.

4 SHEETSSHEET l.

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W. E. TRENT.

GRINDING MACHINE.

APPLlcAIloN msu sw. 3. 1920.

1,405,109, Patented Feb.7,1922.

4 SHEETS-SHEET 2.

W um! l! N i 7 1 f W. E. TRENT.

GRINDING MACHINE.

APPLICAHON HLEU sums, |920.

1,406, 109, I Patented Feb. 7, 1922.

4 SHEETS-SHEET 3.

www Eben@ W. E. TRENT.

GRINDING MACHINE.

APPLICAHON HLLD sums, |920.

1,406,109` imma Feb. 7, 1922 4 SHEETS-SHEET 4.

, in the smaller tubes.

entre STATES PATENT orifice.

/QZTER ELDWIN TRENT, OF WASHINGTQN, DISTRICT OF COLUMBIA., AS-SG-NO-R T0 TRENT PELOCESS CORPORATION, OF -WASELI1\`I'G'LO1\T, DISTRICT 0F CULUMBCA, .A

CGRPRATXON OF DELAWARE.

GRINDING MACHINE.

Margine.

Specification of Letters Patent.'

Patented Feb. "Y, 1%?22.

.Application filed September 3, i920. Serial No'. 407,867.

wherein the parts are associated and formed,

so as toproduce a maximum efficiency, while employing a minimum amount of power.

It is a further object of the invention to provide a rotary balanced grinding machine of a positive multiple stage construction, in

which the material to be reduced, first passes from the source of supply in one direction through a pulverizing tube to be partially ground therein, and then passed" through la second tube in an opposite direction prior to the discharge of the comminuted material.

With the foregoing conception .in mind, the invention preferably'comprises a multiple stage grinding machine having a central grinding tube that receives and partially reduces materialsied thereto, which niaterials are then substantially equally distributed to a series oi pulverizing tubes disposed circularly around the central tube to balance the machine, and through which tubes the material must pass before its disl charge to undergo av fine reduction therein,

' lt is a still further obj'ect oi the invention to provide multiple stage grinding machine having a central tube provided with grinding rods or balls of sizes larger than the sizes of the rods or balls disposed within the circularly disposed tubes surrounding the central tube so as to most effectively produce the stage of reduction that is to take place The invention also has among its objects the provision of a balanced grindirig machine in which the component parts' of the machine are entirely independent, thereby melting treatment for a specified travel or time of treatment before passing from one stage to a following stage. Further, in case of break# age, or Wear, any 'component part may be removed, and repiaced. Without the' necessity oi: changing other 1ortioiis thereof.

the material `positivelyl subject to y The invention further contemplates the provision of a grinding machine, capable of either ivet .or dry grinding. tor Wet grinding, water is introduced te the central grinding tube With the material, and

-then distributed to the circularly disposed tubes With-the partially' pulverized material. 1f the material is. to be ground dry, 'the same is fed into the central tube, and an air blast of suiiicient volume .and velocity is introduced to 'pick up and carry line materlal's in suspension that have undergone suiiicient pulverization, Whilev the coarser .materials are being acted upon by the grinding rollers, and when reduced to the When used f proper degree of fneness, are carried by the air blast to a point of discharge.

u From a more specific view, the invention consists of a balanced multiple stagegrinding machine, having a common central grinding tube, provided with relatively large grinding rods, balls, or pebbles, and

in communication with a plurality oil cir? cularly arranged auxiliary tubes, supported upon the central tube, and carried in unison therewith. The material introduced the central tube is compelled to pass therethrough to undergo pulverization., after which the same 'is equally distributed to the various circularly disposed tubes to iurn ther reduced, and caused to travel through sucli tubes toa point of discharge. It willbe observed that the material introduced to the central grinding tube must pass through one tube zuid then to and through. a second tube in a circuitous path, so that sufficient time and travel during grinding is provided, yet at the same time, to enable the machine to be constructed with but a relatively shortk length. l y

In the accompanying drawings l have disclosed several embodiments of the inven tion, but I Wish it to be understood that this disclosure is merely made -for the purpose of illustration,v and t ie construction herein illustrated and described be changed within the scope of the claims Without de,

Fei) Elin tube pa' tu y, igure Els ajslightlymodified form of the ,invention, i

yf., l'Referring nowmore' particularly to' the drawings, Dwherein likeieference characters indicate corresponding parts, the numeral 1 Y 'designates Aasuitable base having arranged 'thereon the vertical standards 2, which constitute the supports 'for the bearings 3, and

' 4, of the machine.

The grinding. machine consists of aleen-1 tral grinding'tube 5, supported in the bearings 3 andy 4- having vannular collars 6, disposed within the recesses in the Vbearings 3 andz4, for the purpose of preventing the lateral .movement of the central tube during its rotation. lThis tube, at its forward end, 4is

provided with a feed chute 7 of a curved formation, entering the central portion 8 of an end plate 9 of t e central tube 5, and positioned so as. to pass through a trough 10.,

- feed trough supported upon the base 1 of themachine during the rotationlof the central tube. The feed 7 is additionally supported by 4a bracket 11, and the length thereof may vary depending upon the quantity of material that it isl desirableto feed to the central tube from the 10, during a single-rotation of the tube. i

' The central tube 5 is of 4a vrelatively short with a multitude of grinding rods 19, they `saine extending substantially throughut the length of the tube to a point adjacent the screen 20; These rods, as disclosed in the cross Vsectional view, are of considerable diameter, and serve to reduce partially the rel,- atively large comminuted material intro-` "toi uduced to the central tube 5 by the feed 7 dur- "ing the passage of this materiaal through the tube. The end plates Pof the tube are f united thereto b bolts and nuts, so that said plates may be 'reely removed, for the urpose of gaining access to the interior o the tube. In thev prior. art, diliculty has been experienced in providing a rinding machine having a sufficient in ing area effectively to reduce material to an exceedinglyfine state of division without making the Grinding tubeof' great length, resulting in the mill being subjected to tremendous weight between its widely separated bea-rings. To obviate this" difiiculty, and yet at the'same time secure a maximum grinding eilig ai@ interior of che grin-a.

area, I have disposed around the central grinding tube 5, a plurality of auxiliary grinding tubes 20,21, 22', 23, 24 and 25, six

- tubes being shown in the present illustration for the purpose of completely surrounding the central tube 5, but it Will be manifest. that any number/of tubes may be employed, this being largely dependent upon the size of the circular tube, and the working conditions for which the mill is to be utilized. It willbe appreciated that by arranging the circular tubes around the common central tube in the manner disclosed, the machine is balanced, and only-a minimum amount of power is necessary to rotate the grinding machine. The exterior4 tubes 20, 21, 22, 23,'.

24 and 25, are maintained in their proper relation upon the central tube 5 by the rods 26,

and turnbuckles 27 connecting sections of' said rod. The turn-buckles engage plates 28 to prevent injury to the tubes when the rods vare tightly fastened thereto so as to cause the outer row of tubes at all `times to rotate with the central tube, and permit no independent niovement' of said tubes relatively to one another. Each circular tube is provided witli suitable grinding rods 28, which are of sizes considerably less than 'the sizes of the rods 19 in the tube 5, inasmuelnas the material delivered to the outer circularly arf rangedl tubes is partly reduced, and the grinding area of these tubes is governed so as to accord with-the 'stage of reduction that is to take place in the outer tubes. While I have shown grinding rods as a grinding medium, it will be appreciated that balls, pebbles, or tlielike, may'be used with favorable results, the sizes being governed by the saine principle as where rods are employed.

Leading from the central tube 5, and

lcommunicatingl with each outer tube 20, 21,

22, 23, 24, and 25, is a feed conduit. 30, six of these conduits being disclosed, ,as one is conduits SO-communicate with the interior of the central tube 5 at one end receiving ma vprovided for each outer grinding tube. The

terial that is passed through said tube. which material is transferred or delivered'to the outer grinding tubes to undergo a further reduction thereimduring the passage of such material through said tubes-to its point of discharge. The mateI 'al introduced to the central tube is usuaLy equally distributedy to all of the outer tubes, eaoli'tilbe receiving its proper charge at one stagefof itsv rotation, which charge passes through the tube, and is finally discharged in' a manner which will be hereinafter described.- The material fed to the central tube 5", 'after' being re duced therein, enters the outer row of tu'bes, the partially ground material passing to the' tubes disposed beneath the `center `ofthe main tu'be 5 tl'irough the conduits 30, in the disclosure shown in*v Figurey 2, the'tubes 21, 22 and 23, are receiving a supply of partially ground material through their feed pipes 30, the continued rotation of the material causing the succeeding tubes 2A, 25 and 20, to receive theircharge when they lreach the proper position, while the filled tubes are rotating to effect a grinding of the material introduced thereto. After the material'has passed through the outer tubes, andhas been reduced therein, the same is discharged from each tube by Athe curved discharge pipes 32. It will be seen that no material can be discharged from aI tube when the discharge pipes are in an upwardly disposed position, but when themill rotates the tubes are successively brought to vthe position disclosed in the lower portionI of Figure 2, wherein the discharge pipes 32 are directed downwardly into the trough 33, and

. the finely ground material that has worked through the outer tubes is charge successively into tiis trough. As has been stated, the material is successively discharged from the various outer tubes, and.

` the 'operation of the machine is continuous,

grinding area.

inasmuch the material is being always introducedtothe central tube, undergoing a preliminary treatmentrtherein, and then sub-A stantially equally distributed and caused to pass through the ou i' tubes 20 to 25 inclusive,thepath"ef1hematerial being a circuitous'onerso as to present a] maximum In Figure 5 of the drawings closedanother form of the invention, which is designed for dry grinding any substance.

In this form, coal, or other material, is intro-v duced to the hopper 34, and fed 'by the conv eyor 35 to the central grinding chamber .36 mounted upon suitable standards 38 for a rotary movement.- Air is injected bythe pipe 39, for forcing the material through the central tube 36, the material passing therethrough and being partially ground by rea-l son of the grinding rods disposed therein. When the material is ground to the desired iinenessin the tube 36, the air current picks up the finer particles ofthe material, carries the same through'the discharge pipes 40 in communication' with one endl of the tube 36, and also with the auxiliary tubes 41, six of thesetubes being disclosed, which tirbes are mounted in the same manner as disclosed in' connection with Figure 1. The tubes 41 likewise have grinding rods, so that the partially ground material is further-*reduced in said tubes during the rotation thereof, and afterl passing through the tubes, discharges .in theair current through the pipes 42, passing between'the tubes to an opposite end of thecentraltube 36,- which is separated from the remaining rtiony of the-tube by the partition 43. e air. carrying the fine material' in suspension', then passes through the discharge pipe 44 intothe dust collector 45, which is of any conventional type, the

rm'itted to dis-l have dis-.

of the machine, the operation may be briefiy stated as follows:

Assuming that the apparatus shown in -Figures -1' ands 3, and intended for wet grindingis. to be used, the material in a comminuted state and mixed with water, is introduced to the feed trough 10.4 The central grindin tube 5 is then rotated'by means Vof the pul ey 17. and gears 12, which impart rotation to the central tube, and the circular tubes? carried thereby. The material must pass through the 'central tube, being acted upon by the tumbling rods 19, which serve to reduce the same to a relatively fine mesh, after which, "said material is discharged through the discharge conduits 30 in substantially e ual proportions to each o f the circular tu es 20 to 25, inclusive; ina successive manner. That is, one tube receives its supply when-it reaches a given position during its rotation, and a second tube then moves into position to receive its supplyy from the main 'tube 5. The material, after being .introduced to the circular tubes 2()V to 25, inclusive, is compelied to passtlierethrough, being further pulverized by the reducing rods 19 tuinbling therein, and after passage through said tubes, the 'material is discharged by the curved discharge pipes 32, into the 4trough 33. It will be noted that the material 'is compelled to travel in a circuitous path, and .that the operation of the machine is ay multiple stage one, permitting the material to be reduced to a minimum degree of i'eness.

Should it be .desirable to pass the material through more than two of the grinding tubes, it will be appreciated that the outer tubes 20 to 25, inclusive'niay be arranged in series, so that the material introduced to any one ofthese tubes through the central tube 5, may be caused to ass back and forth,

through any desired nu ber of tubes, in a circuitous path, prior to its discharge. This construction would only be necessaryl wherev the material is'exceedingly hard and slow to grind and a fineness desired.

If the material is to be ground in a dry state, then the apparatus ,shown in Figure 4 is employed, the material being fed into the hopper 34, and by the air, passing through the pipe 39, is forced into the central tube 36. The material-undergoes partial reduction therein, the air .current picking up particles of the .material of the desired fineness, carrying them through the feed pipes 40 into product of excessive4 iso the auxiliary grinding tubes lll. Here the grinding of the material is completed, the air current carries the pulverized material through 4the discharge pipes 42, the pipes'gflll, and into the dust collector 45, where'the comminuted material is collected andthe air exhausted, and passed together with any included particlesto the air compressor 47 to be returned to the nozzle,

Having thus described the invention, what I claim is: v

l. In a grinding machine, the combination with a common grinding tube having grind ing elements therein, means lor introducing material to said tube, a 'plurality of 'grind- 'ing auxiliary tubes adapted to move in unison therewith, means establishing a communication between one end of the common grinding tube and each of said` auxiliary grinding tubes to permit material that has passed through the common grinding tube to be introduced to one oi said grinding tubes, and a separate discharge for each grinding tube disposed at a point opposite the feedinlet thereto and discharging the material into the atmosphere.

2. In a grinding machine, the combination with a common grinding tube having a feed ing inlet, and provided with a grinding medium, means for mounting said tube for a rotar movement, a plurality of auxiliary grinc ing tubes carried by said common tube, and parallel therewith, means 'for firmly uniting said tubes to the central chamber to cause the same to rotate in unison therewith. grinding devices in the tubes, separate means establishing communication between the central tube at a point remote from its inlet and each of the auxiliar"Y tubes for discharging partially ground material that has passed through said central tube to one ot 'said auxiliary grinding tubes, and discharging means for said auxiliary grinding tubes for discharging material that has passed therethrough. l"

3. In a grinding machine, the combination with a central grinding tube, a feeding in let thereto, means for mounting said tube for a rotary movement, a plurality ot parallel grinding tubes Surrounding said central tube and adapted to move in unison there with, grinding elements carried by said central :tube and Said grinding tubes, and separate means connecting said central tube with each of said surrounding grinding tubes for delivering material thereto to be passed through said parallel grinding tubes respectively in a circuitous path, and a discharge pipe leading from each of said surrounding tubes.

4. A grinding Amachine having a grinding tube mounted fora rotary movement having grinding elements therein, and a second tube of elongated formation having imperforate side walls and provided with shiltable grind ing elements disposed in. parallel relation therewith and driven with said first tube as a unit and in communication with one end of said first mentioned grinding tube, means for feeding material to said first' mentioned grinding tube -to pass therethrough, and to be then delivered to the last mentioned tube to travel lengthwise 'through said tube prior to its dischar e, and a discharge `lor said last mentione tube.

5, A grinding machine-having a primary grinding tube, and au auxiliary tube having grinding devices therein in communication therewith and movable with said ,primary tube as a unit, disposed alongside the main', tube, and presenting side walls de ,iningse l grinding areas which are imperforate and".

grinding devices in said auxiliary tube,`r` means for rotating said tubes, means for feeding a materml to the primary tube yto be passed therethrough, and to be then de'- livered to the auxiliary tube, said primary and auxiliary tubes beingdisposed side'by side to cause the material introduced to the primary tube pass through said primary and auxiliary tubes lengthwise in a cir-k cuitous path prior to its discharge. V

6. ln a balanced grinding machine, the combination with a central grinding tube` having grinding elements therein,'of a plu. rality olf auxiliary tubes arranged around said central tube in parallel relation therewith, said central and auxiliary grinding tubes having elongated grinding areas surrounded by imper orate walls and ,provided with. shittable'grinding devices, means for Vfeeding material to the central tube, means for rotating said tube, and commun1catioiis`- between one end of said central tube andl" the auxiliary tubes to cause the material introduced to the central tube to travel lengthwise through said central and. yauxiliary tubes in a circuitous path prior to its fdischarge. 7. In a grinding machine, the combination' with a central grinding tube, of' bearings therefor, auxiliary grinding `rtubes surf rounding said central grinding tubes and in' parallel relation therewith grindingdevices disposed within said central andy auxiliary tubes, means for uniting said auxiliary' tubes to` said central tube to cause` all of said tubes to rotate in unison, a feed at one endet such 'central tube, discharge devices atlthe opp'osite end of Said central tube communlcating with the auxiliary tubes tojdeliver matoria/l from said central tube to the auxiliary tubes L iliary tubes prior to its' discharge; 8. In a grinding machine, the conubination/` with a central grinding tube', oifilbearings therefor, auxiliary grinding tubessurround'- pass lengthwisev throughisaid auxing said central grinding tubes land vin parallel relationtherewith, grinding devices "dis posed within said jcen'tral'and auxiliary nieuwe tubes, means for uniting said auxiliary tubes to said central tube to cause all of' said tubes to rotate in unison, a feed opening at one end eJE such central tube, dischargev devices at tl e opposite end oisaid central tube, cornnjiunicating with the auxiliary tubes to deliver material from said central tube to the ausiliary tubes to pass through said auxiliary tubes prior to its discharge, and means for :feeding the central tube comprising a scoop carried tiereloy and movable in a trough adapted to receive a supply of teriala 9. A balanced grinding machine comprising a rotatable central tube having. a feed inlet, or auxiliary tubes having imperforate walls intermediate their ends disposed around said central tube, means for uniting said auxiliary tubes to said central tube in proper spaced relation to rotate therewith .as a unit, the central and auxiliary tubes being provided with grinding devices for reducing material .introduced thereto, said central tube communicating at one end with said auniliarv tubes 'for distributing the material.

parti ly ground in the central tube to the auxiliary tubes to 'eiiect a further reduction ci? t material during its passage thro the auxiliary tubes 'prior to its discha- 'ltl A balanced grinding machine comprising a rotatable central tube having a feed inlet, of auxiliary tubes disposed around. said centra-l. tube, means for uniting said. auxiliary tubes to said central tubes in goroper spaced relation, the central and aus.- ilisry tubes having imper'orate walls intermediate their ends and being provided with grinding devices for reducing materialin- .troduced thereto, and said central tube communicating at one end with said auxiliary tubes for distributing the material partially ground in the central tube 'to the auxiliary tubes tcoi'ect a further reductionithereo pier to' its dischar e, the material being forced to travel in a circuitous path while undergoing pulverization.

Ill. A grinding machine provided with a rotatable grinding chamber having grinding de es and a support therefor, auxiliary grinding chambers disposed alongside said main chamber and adapted to rotate therewith unit, means establishing communication between said auxiliary and main chambers, the walls of the auxiliary and main chambers defining grinding areas being imperforate to cause materia-l introduced to the.

main chamber to travel in a closed path' 'through said chamber and then lengthwise through said auxiliary grinding chambers "prior to its discharge, and discharging devices `tor said auxiliary chambers.

l, a grinding machine, the combina-` tion with ya central grinding chamber having a iis-ed niiet, means i'crsupgrorting said chainber for 'rotary' movement, a plurality of grinding chamber, 'provided 'wi auxiliary grinding chambers disposed alongside saidA main chamber and' adapted to rotate therewith as a unit, grinding elements carried by said central and auxiliary grinding chambers, independent sources of communicationconnecting said central chamber with each of said auxiliary grinding chambers for deliveringmaterial thereto to he passed through said chambers in a circuit-cus path, and a discharge from each of said auxiiiary grinding chambers.

13. A grinding machine comprising a rotatable grinding chamber having grinding devices therein adapted to receive mate dal, means for supporting chamber for a rotary movement, a second chamber provided with grinding means adapted to rotate with said irst mentioned chamber as a unit, said .last mentioned chamber being positioned alongside the tirst mentioned chamber, and constructed whereby material progressively passes through said chambers in a circuitous path prior to its discharge, and discharo'ing means for said last mentioned chamben Y 14a A grinding machine hav iff a main h reducing devices adapted to receive material, means for supporting said chamber for a rotary movement, an auxiliarT chamber having grinding elements adapted to rotate with said nialn chamber as a. unit and 1n communication therewith, said auxiliary chamberexl5. A grinding machine having a grind-f 7 ing tube adapted to receive grinding devices, feeding means for said tube, means for supporting the tube for a rotary movement', an auxiliary chamber having grinding means rotating with said irst mentioned chamber as a unit, and communicating therewith, said `auxiliary chamber being positioned alongside the primary chamber, both of said chambers having iinperforate walls. presenting a. closed path for material introduced thereto', whereby said material progressively travels lengthwise through one chamber and then through the other prior to its discharge.

i6. grinding machine having a rotatable grinding tube provided with grinding devices, an auxiliary tube lyingalongside said main tube, rotatingas a. unit therewith, and a communication between said tubes, the walls of said tubes deiining grinding arcas being imperforate whereby said tubes present a closed path for material introduced. thereto to cause said material to progressively travel throu'rdi length. of tl- "rind-- ing area of the ci e t be an than throi gh the other prior to its sisch and then distributed to the auxiliary tubes for passage through said tubes prior to dis- 'charge i 18. A tube mill, comprising a central tube and surrounding parallel tubes united there-A to so as to rotate as a unit, grinding elements in each of said tubes, feed tubes leading from one end of seid central tube te each efsaid surrounding tubes 'at adjacent ends, and sep- .,arate discharge tubes for said surrounding tubes leading therefrom adjacent the feed end of said central tube, substantially as described. j

19. A tube mill, comprising a central tube, and surrounding tubes substantially parallel with the central tube united thereto and rotatable as a unit, grinding elements in each of said tubes,y means for feeding material from the central tube to the surrounding tubes after the passa-ge of the material through the central tube, and discharge means'fromeach of said surrounding tubes leadlng therefrom opposite the inlet to said tubes, substantially as described. f

In testimony whereof I aliix my signature.

WALTER EDWIN TRENT. 

